They had barely arrived at base camp and the peak was already out of sight.
Pompey tried their best to scale the Doncaster mountain after conceding two goals before some fans had got comfortable in their seats.
Liam Mandeville opened the scoring for the hosts at the Keepmoat Stadium, while Christian Burgess then turned the ball into his own net.
Some comical defending gifted the visitors a lifeline, only for the ascent to become treacherous once more when Dion Donohue was sent off.
And while Kenny Jackett was pleased with his side’s battling qualities, he bemoaned their sloppy start.
The Blues boss said: “Doncaster had three clear-cut chances in the first six minutes of the game and took two of them.
“We’ve gone away to Northampton and Scunthorpe recently, and given ourselves a mountain to climb – and we did the same again.
"I can’t say that we were necessarily outclassed – we just got it wrong in the opening stages and that cost us."
“For the first goal, Tommy Rowe’s gone inside two of our players and we know he’s capable of that, so defensively it was poor.
“There was some misfortune about the second one, but we’ve just given them too many opportunities.
“We’re the away side and we need to start strong to make sure that we stay in the game, but instead Doncaster found themselves in pole position.
“There were some key moments after that, with Christian’s header cleared off the line and Conor Chaplin had a free-kick that hit the woodwork.
“We kept battling away, got one back and even after going down to 10 men we had a good chance through Jamal Lowe.
“But we shouldn’t be putting ourselves into the position where we’re giving ourselves those problems and we’ve done it too many times.
“I can’t say that we were necessarily outclassed – we just got it wrong in the opening stages and that cost us.”
Jackett had no complaints about Donohue’s dismissal for an off-the-ball clash with Rovers substitute Niall Mason.
He said: “He’s kicked out at the player and you just can’t do that. He’s given the referee the opportunity to send him off.
“Dion has to take the responsibility for his actions. I’ve spoken to him and told him exactly that.
“We can talk about the referee or their bench, but if you kick out – even if it was just a small flick – you open yourself up to get a red card.”